xianlian
幼苗
共回答了23个问题采纳率:95.7% 举报
(1)见解析 (2) 25°
解:(1)由圆I与AC相切于点E得IE⊥AC,结合HI⊥AH,得∠AEI=∠AHI=90°,所以A,I,H,E四点共圆.
(2)由(1)知A,I,H,E四点共圆,所以∠IEH=∠HAI.由题意知∠HIA=∠ABI+∠BAI=
∠ABC+
∠BAC=
(∠ABC+∠BAC)=
(180°-∠C)=90°-
∠C,结合IH⊥AH,得∠HAI=90°-∠HIA=90°-(90°-
∠C)=
∠C,所以∠IEH=
∠C.由∠C=50°得∠IEH=25°.
1年前
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